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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
20
pubmed:dateCreated
1999-6-17
pubmed:abstractText
Plasmepsin II, an aspartic protease from the human intraerythrocytic parasite Plasmodium falciparum, is involved in degradation of the host cell hemoglobin within the acidic food vacuole of the parasite. Previous characterization of enzymatic activities from Plasmodium soluble extracts, responsible for in vitro hydrolysis of erythrocyte spectrin, had shown that the hydrolysis process occurred at pH 5.0 and involved aspartic protease(s) cleaving mainly within the SH3 motif of the spectrin alpha-subunit. Therefore, we used a recombinant construct of the erythroid SH3 motif as substrate to investigate the involvement of plasmepsins in spectrin hydrolysis. Using specific anti-plasmepsin II antibodies in Western blotting experiments, plasmepsin II was detected in chromatographic fractions enriched in the parasite SH3 hydrolase activity. Involvement of plasmepsin II in hydrolysis was demonstrated by mass spectrometry identification of cleavage sites in the SH3 motif, upon hydrolysis by Plasmodium extract enzymatic activity, and by recombinant plasmepsin II. Furthermore, recombinant plasmepsin II digested native spectrin at pH 6.8, either purified or situated in erythrocyte ghosts. Additional degradation of actin and protein 4.1 from ghosts was observed. Specific antibodies were used in confocal imaging of schizont-infected erythrocytes to localize plasmepsin II in mature stages of the parasite development cycle; antibodies clearly labeled the periphery of the parasites. Taken together, these results strongly suggest that, in addition to hemoglobin degradation, plasmepsin II might be involved in cytoskeleton cleavage of infected erythrocytes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14218-23
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Plasmepsin II, an acidic hemoglobinase from the Plasmodium falciparum food vacuole, is active at neutral pH on the host erythrocyte membrane skeleton.
pubmed:affiliation
Laboratoire de Biologie Parasitaire, Muséum National d'Histoire Naturelle, EP 1790 CNRS, 61 rue Buffon, 75231 Paris Cedex 05, France.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't